Well to be fair, GaMERCaT did find Glitch while he was playing Pokemon Red. I know that’s not WHY he’s crying, but who knows, maybe subconsciously, it brought back the joy of when they first met? No? okay…

There’s numerous different kinds of MissingNo. Some are harmless, a few will corrupt the Hall of Fame or PC Boxes, and one particular MissingNo (which can only be gotten by using FLY to Cinnabar Island, then traveling back to seafoam island with repel, then traveling through the cave and surfing on the edge of… I believe it was the first room with a surfable pool) will simply break your game. Permanently.

How do I know? When I was 10 yrs old, I didn’t believe it could corrupt the cartridge. The game would still load, but everything was screwy and it played random noises instead of music. There was no option to load or start a new game anymore. Oh well.

Each Missingno looks different, the classic is the L shaped one, but there’s also a small square, a large square, and sometimes it comes up as Gengar or Kangaskhan but with a level greater than 100. Depends on where you go and whether you surf or fish while on land. The one which broke my game, however, was just a long row of HP bars covering roughly the top 1/3rd of the screen. Attacking it made the massive HP bar drain for about 45 seconds before resetting to full and then draining 2 or 3 more times. After waiting for the animation to finish the HP bar would get larger and cover even more of the screen. Capturing it… Well, don’t do that.

People have found ways to control this glitch and related glitches now. This sort of thing is actually used in the “catch 151 pokemon” speedrun, in which the game is heavily glitched and all pokemon are caught in about two hours. Nice thing about emulation is you can’t break a cartridge!